Computing devices are routinely used at work, at home, and everywhere else. Computing devices advantageously enable electronic communication, data sharing (e.g., documents, pictures, music, film, etc.), the use of application-specific software, and access to information for electronic commerce through the Internet and other computer networks.
The term computing device generally refers to desktop computers, server computers, laptop computers, mobile computing devices (e.g., personal digital assistants (PDAs), cell-phones, etc.), as well as any other type of computer system. A computing device typically includes a processor and a memory as well as other types of electronic devices, such as, a disk drive.
Disk drives typically employ a moveable head actuator to frequently access large amounts of data stored on a disk. One example of a disk drive is a hard disk drive. A conventional hard disk drive has a head disk assembly (“HDA”) including at least one magnetic disk (“disk”), a disk clamp and a disk fastener (or screw) to mount the disk to a spindle motor that rapidly rotates the disk, and a head stack assembly (“HSA”) that includes a moveable actuator arm and a head gimbal assembly (“HGA”) with a moveable transducer head for reading and writing data. The HSA forms part of a servo control system that positions the moveable head over a particular track on the disk to read or write information from and to that track, respectively.
Due to the cost competitiveness of the disk drive industry, the components of a disk drive need to be assembled in a very precise and cost effective manner. In order to be cost effective, complex components of the disk drive, such as disk clamps, disks, spindle motors, HDAs, HGAs, etc., need to be assembled, with fasteners, such as screws, in a very time effective manner with a very low error rate—even though many of the components require highly precise assembly. Also, many of these types of components often need to be assembled in a very clean fashion in which debris and contamination particles are kept to a minimum. Further, as disk drives are being actively utilized more and more by users as standard hard disk drives, enterprise hard disk drives, moveable external disk drives, and/or for use in smaller computing devices such as laptops and mobile devices (e.g. PDAs, cell-phones, etc.), they are increasingly requiring smaller and smaller components for assembly.
In particular, the assembly process for hard disk drives is requiring the use of smaller and smaller screws. These smaller screws are becoming very difficult to feed with currently utilized feeding mechanisms because of the small screw height to head diameter ratio (i.e., the aspect ratio). In fact, many hard disk drives are utilizing screws with an aspect ratio close to 1.0 (i.e., a low aspect ratio), which are encountering many problems in the assembly process.
Disk drives need to be assembled with more reliability, performance, and compactness when utilizing screws with low aspect ratios. Presently, some screw feeders utilize a vibrating rail to transfer screws to a tube for delivery to a screw insertion assembly machine for mounting the screws to components of the disk drive.
Unfortunately, presently utilized screw feeders are encountering many problems with low aspect ratio screws. In particular, a common implementation in which a screw feeder utilizes a vibrating rail that directly drops screws into a screw guide tube encounters many problems because of the screws falling away, jamming, and flipping during the feeding process. Therefore, it would be beneficial to provide a screw feeding apparatus that can feed screws into a screw guide tube in a fashion that minimizes screws falling away, jamming, and flipping.